Aluminum Dross Processing


Aluminum dross, a byproduct of the aluminum melting process, is a mixture of aluminum, its oxides, the oxides of alloying elements and less frequently halogenides, carbides and nitrides.
Dross has some good benefits, especially considering tension strength and depending on further conditioning steps can be very useful further on.

Dross is a by-product of all aluminum melting processes. Depending on scrap type, alloy treatment and melting equipment, the amount, metal content and properties of dross vary in a wide range. Dross is a mixture of aluminum, aluminum-oxide and oxides of alloying elements, additionally halogenide, carbide or nitride compounds of these metals are regularly encountered. Typically dross contains a large amount of metallic aluminum. This is mechanically fixed in a cellular structure of aluminum oxide, which has tension strength great enough to keep aluminum 20 times of its own weight bonded. As dross also contains finely dispersed gas bubbles (foam structure), it easily separates from the aluminum melt due to the reduced density.

The following process parameters have a strong influence on volume, morphology and the metal content of dross:

  • Surface/volume ratio of the scrap
  • Type (organic, inorganic and amount of impurities
  • Melting conditions and melting equipment
  • Melt composition (especially Mg, Na, Li, Ca-content)
  • Refining procedure
  • Way of dross removal (temperature, tools)
  • Cooling parameters of removed dross

A direct comparison and evaluation of the various dross conditioning processes is difficult, as the raw material source is different. Generally modern processes are based on a fast quenching step in order to avoid an oxidation of the incorporated aluminum metal droplets. It is followed by a mechanical beneficiation step which removes as much oxide as possible. Alternatively a direct melting of the > 1 mm fraction is state of the art. The by-product has to be dumped or processed separately in a slag treatment plant, the <1 mm fraction (dross residue) can be sold to the steel industry for deoxidation purposes.

Figure 1: Formation of Dross

a) Surface oxidation of melt.
b) Crushing of oxidic skin by bath movement.
c) Sinking and floating of oxidic particles.
d) Conglomeration of oxidic particles.
e) Interspace filling up by metallic aluminum.
f) Inside oxidation of dispersed aluminum.
g) Skimming of dross from melt bath surface.
h) Metallic aluminum drip off and follow-up oxidation of solids during dross cooling

Table 1: Composition of dross

Figure 2: Dross

기술 자료 검색

검색할 어구를 입력하십시오:

검색 범위



Total Materia는 다양한 나라와 규격에 따른 수천개의 알루미늄 재질에 대한 정보를 포함하고 있습니다.

재질의 화학적 조성, 기계적 특성, 물리적 특성, 고급 물성 데이터 등의 전체적인 특성 정보들을 어디서든 검토하실 수 있습니다.

고급 검색을 이용하여, 검색 조건의 재질 리스트에서 '알루미늄'을 선택합니다. 검색 범위 좀 더 줄이기를 원하신다면 국가/규격과 같은 다른 조건을 지정할 수 있습니다.

검색 버튼을 클릭합니다.

선택된 정보에 부합하는 일련의 재질이 검색됩니다.

결과 리스트에서 재질을 선택하시면, 일련의 규격 사양 소그룹이 나타납니다.

여기에서 선택한 재질의 특정 특성 데이터를 검토하실 수도 있고, 강력한 상호 참조 표를 이용하여 유사 재질이나 등가 재질을 검토하는 것 또한 가능합니다.

자세한 특성 데이터를 보시려면 특성 데이터 링크를 클릭하세요.

Total Materia 데이터베이스를 사용해 보실 수 있는 기회가 있습니다. 저희는 Total Materia 무료 체험을 통해 150,000명 이상의 사용자가 이용하고 있는 커뮤니티로 귀하를 초대합니다.